US2232035A - Carburetor - Google Patents

Description

Feb. 1s, 1941y V A, L, MENNESSQN 2,232,035

' cARBURgToR Filed Nov. 5, 1958 'Patented Feb. is, 1941 CARBURETORV y Andr Louis Mennesson, Neuilly sur A Seine,

France, assigner lto Societe Anonyme Solex, 4 Neuillysur-Sene,- France, a society of France Application November 5, 1938, serial No. 239,148

In France December 2, 1937 2 Claims. ,(cl. 26T- 41) The invention relates to carburetor for internal combustion engines.

. It is known that in certain cases, where theA power to be furnished'by an internal combustion '1 engine is to be increased,'it is necessary to enrich the mixture. In particular, sucha ,device-is of special interest in the case of aircraft engines, principally of the air-cooled type, for which the cooling becomes insunlcientwhen the machine is .1H rising and when, in consequence, its speed is insuiiicient to cool the engine properly,especially as an additional load is imposed upon this latter .during the ascent.

The present invention hasfor'its object `to provl5 vide a. carburation device, for engines of the kind in` question, by which an automatlcrenrichment of the 'carburetted mixture is obtained when the engine is caused to assume an-inclined position with respect to its normal position, this enrich- 0 ment being all the greater .asthe inclination is the greater.

The invention consists, principally, inmaking carburation devices of the kind in question com'- prise means adapted to enrich the combustible 5 mixture and of which the putting into or out of action is determined by the height of the level of the f uel at a suitably chosen point of the constant level chamber of the carburetor, this height itself being a function ofthe inclinations of the 20 carburetor.

.'Ihese include a second arrangement consisting :1.3 in acting on the delivery'of fuel, furnished by the means adapted to enrich the combustible mixture, by any known device correcting the value of this delivery as a function of the pressure whichv exists at the air inlet of the carburetor, this corrich the mix-ture by a communication established' between the inlet lconduit and an orice opening into a. well, above the normal fuel level of the .'.0 carburetor, this well being supplied with fuel through a calibrated oriilce.-

They further include a fourth arrangement consisting in forming the means adapted .to enrich the combustible'mixture by a communication .7.3 established between the inlet conduit and several orifices', opening at -diiferent heights into a well above the normal fuel level of the carburetor, this well being supplied with fuel through a. calibrated orifice.

co They also. include a fifth arrangement, consisting in constituting themeans adapted tu enrich thecombustible vmixture 'by a calibrated communication establishedbetween the inlet conduit andan orifice opening into a chamber below the level of thefuel, the opening of this communi- 5 cation being controlled by'an Vauxiliary oat, distinct from the float which determines the constant level of the carburetor. r

Additionally, 4they include a sixth arrangement consisting in constituting the means adapted to enrichthe combustible mixture so that they can cause variations in the passage section of a calibrated orifice forming an emulsion -air inlet, the said means Ibeing actuated by an auxiliary float distinct lfrom the float which4 determines the 1`5 constant level inthe carburetor. Y

They further includey a vseventh arrangement consisting in providing the means :adapted to enrich the combustible mixture with an obturator -controlled by hand,- by the controlling member sisting in -providing the means adapted to enrich the combustible mixture with. an obturator controlled by a manometric device, for example, a diaphragm or a piston, the position of which is a function of the differences of pressure between two suitably chosen points of the inlet pipe of the engine downstream and upstream of the regulating valve located in the said inlet pipe.

They also include a nintharrangement, consisting in providing the means adapted to enrich the combustible mixture with an obturator controlled by a barometric capsule subjected to the A pressure of a suitably chosen point ofthe inlet pipe, eitherupstream, or downstream of the regu` lating valve located in the said inlet pipe.

. In order that the invention may b e better understood, it will now be described with reference to the accompanying drawing, which is-given by way of example .only and in which:

Fig. 1 .shows-in diagrammatic `vertical section, a 'carburetor constructed according to the invention and in which the mixture-enriching device opensl into the inlet pipe of thecarburetor.

Fig. 2 shows, similarly, a part' of this same .devic'e in a position other than its normal position.

Fig'. 3 shiws, similarly, a variation of this device 50 for which the mixturesenriching device opens into the principal nozzle systemof the carburetor. Fig. 4 shows, similarly, another variation of the device shown on Fig', l.

Fig. 5 shows, similarly, a part of a carburetor 55 comprising a mixture-enriching device acting on thefuell and controlled by an auxiliary float.

Fig. 6 shows, similarly, a carburetor' comprising a mixture-enriching device acting on the emulsion air and also controlled by an auxiliary float.

cally a carburetor comprising a body I, a. regulating valve 2, a constant level chamber 3 and a principal nozzle system constituted by a well 4 supplied with fuel 'by a conduit 5 with calibrated orifice 6 and the emulsion system of which is inclined by conduits 1 opening at different levels into the well 4 and which are supplied with air through a calibrated orifice 8. As the retarding device does not intervene in the operation, it has not been shown on the drawing.

In the constant level chamber 3, there is formed, with the aid of a partition 9, a well III supplied with fuel by a calibrated orice Il located at a certain distance below the normal level of the carburetor. At the upper edge of the partition 9 there is provided an orifice sufficiently large to permit an adequate air supply to the well I0. 'This device permits of obtaining, in the well I0, a level the height of which is more constant and the surface calmer than in the chamber 3. Into the well I0 opens, a little .above the normal level, a conduit I2 which is extended by a conduit I3 opening, through a calibrated orice I4, at a suitably chosen point of the inlet pipe, for example in the v enturi of the carburetor. This orifice I4 is, in' consequence, subjected to the suction which exists Ain this venturi. A conduit I5 connects the upper part of the chamber 3 to the principal air inlet of the carburetor in order e ,a device which corrects the richnessof the mixture as a function of the altitude. For this purpose, there is located in the conduit 5 and between the calibrated orifice 6 and the chamber Y 3, an obturator 24, controlled by a rod 25 connected to a. barometric capsule 26 the fixed point of which is pivoted at 21. The rod 25 is also connected to an obturator 28 capable of partly obturating the` conduit I3. The barometric capsule `26 is subjected to the pressure which exists in the air inlet of the carburetor.

The device, shown on Fig. 1, functions in the following mannersupposing that the aircraft, on which it is mounted, moves in the direction of the arrow F.

When the engine is in the horizontal position, which is that shown on Fig. 1, it is seen that the combustiblev mixture is assured by the air which enters through the inlet pipe and by the, fuel supplied by theprincipal. nozzle 4 of the carburetor.

The respective dimensions of the calibrated orifice I4 and of the conduit I5are such that, for such a position, the depression, which might occur in the chamber 3 when the obturator I6 re mains open, is negligible.

If the aircraft is rising, the engine and, in consequence, the carburetor tilt in the direction shown on- Fig. 2. At this moment, the level rises in the wellv I0 since there is free communication between this well andthe chamber 3 through the calibrated orifice II and the fuel penetrates by overflowing into the conduit I2. In consequence of the suction which is exerted in the conduit I2 andthe piping I3 through the orifice I4 if the obturator I5 is open, the fuel is immediately aspired by the engine, in addition to the fuel normally aspired by the principal nozzle system 4 whichcontinues to function. There is consequently obtained an enrichment of the combustible mixture introduced into the engine. The value of this enrichment is determined by the dimension of the calibrated orifice II and, in addition, a slight variation of the delivery by this orifice takes place according as the -immersion of this latter is more or less great. lar, the more the inclination increases the greater the immersion, with the result that the delivery through the orifice II becomes greater. An increase of the enrichment thus takes place when there is an increase of the inclination. If the Aengine resumes its normal position the level again drops below the inlet of the conduit l2 and the enrichment ceases.

It should be observed that in order to have,

during the ascent, that is to say whilst the ascent ,of the enricher which takes place through the conduitI3.

For this purpose, there has been shown on Fig. 1 a corrector which has been assumed to be automaticv and in which a' barometric capsule 26, which expands when the pressure in the air inlet drops, acts on a rod 25 in order again to close the obturator 24 so as to throttle the delivery of fuel which passes through the piping 5. Naturally, it is supposed that the regulation of this capsule and of this obturator are such that the combustible mixture, introduced into the en- In particugine, is always correct whatever may be the altitude.

The capsule 26 also acts, by the rod 25, on the obturator 28 which regulates the delivery of the fuel passing through theconduit I3. The correction takes place in the same way, that'is to say that when the pressure at the air inlet diminishes, the capsule 26 expands, which has -for effect again to close the obturator 28 while diminishing the delivery of fuel which passes through the conduit I3, this diminution of delivery being all the greater as the pressure is weaker at the air inlet of the carburetor. The obturator 28 and the capsule 26 are regulatable so as to obtain, for all the Apressures at the air inlet, a suitable quantity of fuel delivered by the enricher. Obviously, any other known automatic or nonfautomatic altlmetric correction sysvtem can be utilised.

The obturator I6, located in the piping I3, is providedrin order that the enrichment shall only take place when the engine works in the neighbourhood of a certain power, for example full power. It is in fact when onev is in the neighbourhood of full power that the engine has need of this enrichment called ascent enrichment and it may be that for the mean powers this enrichment is unnecessary. With this object, the obturator I6 is connected to the diaphragm I8 whichis urged by the spring 23 in a direction for which this diaphragm tends to cause the opening of the obturator I6, the two chambers I9 and v20 being connected respectively by conduits 2l and 22to two suitably 4chosen points of the inlet pipe, upstream and downstream of the regulating valve 2. In this way, if the mean powers of the engine are utillsed,'the valve 2 is controlled by a piston or by a barometric capsule,

subjected to the pressure of a suitably chosen point of the inlet pipe, either upstream, or downstream of the regulator valve. 4 s Everything relating to Fig. 1, as also to the following figures, is of course applicable if the engine utilised is an engine charged by a compressor, located upstream or downstream of the carburetor.

, Fig. 3 shows a device analogous to that of Figs.

1 and 2 but for which the piping I3 opens into the nozzle system 4 of the carburetor. The functioning. of such a device is exactly the same as that explained above. y

Fig. 4l shows a variation of the arrangement according .to Figs. 1 and 2 for which the conduit I2 'which' opensl freely into the well IIIhas been replaced by a conduit 29 pierced with several calibrated orifices' 30 situated at dierent heights above the normal level of the carburetor.

This, device permits a greater variation of the enrichment to be obtained, as a function of the inclination. In fact, it is obvious that if the engine inclinesand takes a position similar t that i of Fig. 2, the .aspiration of the fuel is obtained first of all through the lowest orice 30, then through two, then through three, and so on, in proportion as the inclination increases. By suitably calibrating the orifice II and the orifices 30 it is thus possible to obtain any desired progres-` sion for the enrichment.

It is also possible to locate in the conduit I3 an obturator similar to that designated by I6 on Fig. 1, and to control it in a similar manner.

Fig. shows'a device also constituted by a constant level chamber 3 supplied with air by a conduit I 5. Into this chamber opens, below the normal level, the conduit I3 terminated by a calibrated orifice 3l forming the seat of a needle valve 32. 'I'his needle valve can be raised by an auxiliary float 33 pivoted to a ixed point. The other extremity of the conduit I3 opens either into the venturi as on Fig. 1, or into the principal nozzle system as on Fig. 3.

The operation of this device is as follows:

If the engine is inclined rin the same direction as for 2, the fuel raises the auxiliary float 33 which operates the needle valve 32 in such a way that the fuelv can enter the conduit I3 in rger to enrich the mixture admitted to the en- It should be observed that the more the carburetor is inclined, themore the calibrated orice 3| will be immersed and, in consequence, the greater will be the enrichment.

Here yagain, there can be located in the conduit I3 an obturator I6 similar to that shown on Fig. `1.

Fig. 6 shows an enricher device acting on the emulsion air. In this case there is provided by the side of the emulsion system 1, .supplied with air through the calibrated orifice 8. .a snail auxiliary chamber 3l supplied with fuel by a conduit 35 connected to. the conduit l so that the levelwhich is set up in the chamber 3, is the same as that of the chamber 3l. This chamber serves to house a float 39, pivoted to a fixed point 31 and capable of actuating a rocker 38 pivoted at 39 the free extremity of which carries a needle valve 48 which can more or less obturatc the calibrated orifice 3. A tube 4I allows the auxil iary chamber 34 to be supplied with air.

'I'he operation of this device is as follows:

When the engine occupies its normal position, the auxiliary float 36 occupies a position such that the needle valve 80 leaves the calibratedoriice 8 free and allows a maximum air admission into the emulsion system, I f the engine. is inclined in the direction shown on Fig. 2, the level in the chamber 34 drops, the float 36 carries along the rocker 38 and the needle valve 48 engages in the calibrated orice 8, diminishing the aeration of the emulsion, which `results in an increase in the richness of the mixture by an increase of suction on the calibrated orice 6. The greater the inclination becomes, the -greater the yobturation of the orifice 8 and, in consequence, the greater the enrichment. l

Of course the carburetor shown on Fig. 6 can also be provided with a device similar to that of Fig. 1 and which comprises an obturator I8 with its control. In the case of Fig. 6 the diaphragm, the piston or the capsule would act onthe rocker 38 for example by displacing the pivoting point 39 so that the enrichment cannot take place iin-- -obvious that the obturator' I6 or its equivalent for Fig. 6 could-likewise be controlled by hand or Iby a positive connection to the control of the regulating valve 2.

What I claim is:

1. In combination with avehicle having an internal combustion engine for driving the same, a carburetting device for said engine comprising an induction conduit fuel outlet means in saidinduction conduit, a constant level chamber, means to supply fuel under normal conditions from said constant level chamber to said fuel outlet means. a well located to the rear of said constant level chamber, means providing a restricted fuel communication between said weil and said constant level chamber andan air communication large enough to maintain substantially equal pressures in the spaces above the liquid in said well and chamber, whereby when the carburetting arrangement is inclined by uphill movement of the vehicle thelevel o:|'r fuel in said well increases, a normally open conduit having its inlet in said well at a levelhigher than the normal fuel level in said oat chamber and well. and its outlet connected to said fuel outlet means, for enriching the fuel mixture, said conduit being controlled only by the height of the level of fuel in said well, said height being itself a function of the inclination of the carburetting device and consequently of the motor and of the vehicle.

2. A device as claimed in claim l, said normally open conduit having a plurality of inlets at different heights above the normal fuel level in said float chamber and well.

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